<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            padding: 0;
            margin: 0;
        }
        
        div {
            width: 500px;
            height: 400px;
            border: 2px solid black;
            margin: auto;
            display: flex;
            /* justify-content: space-between;
            align-items: center; */
            overflow-x: auto;
        }
        
        p {
            width: 100px;
            height: 100px;
            flex-shrink: 0;
        }
        
        p:nth-of-type(1) {
            background-color: pink;
            /* align-self: flex-start; */
            /* order: 3; */
            /* flex-grow: 1; */
            flex-basis: 200px;
        }
        
        p:nth-of-type(2) {
            background-color: green;
            /* flex-grow: 1; */
        }
        
        p:nth-of-type(3) {
            background-color: purple;
            /* order: -9; */
            /* flex-grow: 1; */
        }
        
        p:nth-of-type(4) {
            background-color: gray;
        }
        
        p:nth-of-type(5) {
            background-color: red;
        }
        
        p:nth-of-type(6) {
            background-color: indianred;
        }
        
        p:nth-of-type(7) {
            background-color: orange;
        }
    </style>
</head>

<body>
    <div>
        <p>1</p>
        <p>2</p>
        <p>3</p>
        <p>4</p>
        <p>5</p>
        <p>6</p>
        <p>7</p>
    </div>
</body>

</html>